Fuel tanks for automotive vehicles have been made from metal and plastic materials. Fuel tanks are formed in various sizes and shapes as required for the various applications in which they are used. Fuel tanks used in passenger vehicles must meet certain requirements relating to, for example, resistance to rupture upon impact and permeability to hydrocarbons in fuel vapor. Typical plastic fuel tanks include a single wall of material and that wall may be formed from a single material or multiple layers of different materials.